This invention relates to the art of telephone systems, and more particularly to a new and improved system and method for automatically configuring a digital telephone computer/telephony interface.
In a basic PBX (private branch exchange) configuration, the PBX is connected between the central office switch and the individual telephone stations. In a computer/telephony integration a computer is connected to one of the station lines to emulate the telephone terminals with the end result of controlling most of the features offered by the PBX through the computer interface. The computer/telephony interface must be configured to meet the characteristics of the PBX. Heretofore, this has been accomplished by providing different hardware modules for each type of PBX and selecting the modules by relay systems or the like. This approach undesirably is hardware dependent, can require a large number of components if many different types of PBXs are to be accommodated, and typically is restricted to a certain range of loop lengths, i.e. line distance from the PBX.
It would, therefore, be highly desirable to provide a system and method for configuring a digital telephone computer/telephony interface automatically or xe2x80x9con the flyxe2x80x9d to accommodate different PBXs. As a result, in computer/telephony integration fewer components would be required with the advantages of reduced board size and lower cost. With such automatic configuring, when the digital telephone system is to be used with a different type of PBX, the necessary changes are carried out internally rather than by external means involving changing or adding hardware.
The present invention provides a universal line driver interface which enables a digital telephone computer/telephony interface to configure itself automatically or on the fly to accommodate different PBXs. The interface is connected to a PBX and to a digital telephone. The interface also is connected to network interface logic. A microcontroller, which is part of the computer in the computer telephony system, is connected in controlling relation to the interface and to the interface logic. The microcontroller under program control changes operational parameters in the interface as a function of electrical characteristics of the particular type of PBX to which the interface is connected. The changes in operation parameters of the interface, in turn, are used to configure the interface logic depending upon the type of PBX. The universal nature of the interface is achieved by adaptability to different transmission and receiver voltage levels and an ability to match a range of telephone line impedances.
The foregoing and additional advantages and characterizing features of the present invention will become clearly apparent upon a reading of the ensuing detailed description together with the included drawing wherein: